One type of gravity feed shelf includes a downwardly tilted planar support surface over which a feeder belt is arranged to slide. Such a gravity feed display shelf is disclosed and claimed in U.S. Pat. No. 4,128,177 issued Dec. 5, 1978. Since each shelf ordinarily includes a plurality of belts and their supporting structures, a display rack according to U.S. Pat. No. 4,128,177 is complicated in construction and is expensive to build and maintain.
Another example of a gravity feed device is represented by U.S. Pat. No. 2,218,444 issued Oct. 15, 1940 which discloses a metal channel intended primarily for use in conjunction with milk bottles in refrigerators. This patent discloses alternative procedures for achieving the desired degree of tilt of the chute. The chute of U.S. Pat. No. 2,218,444 is constructed of metal and does not lend itself well for economical production procedures.